Patent Application
20110146966
1. Field of the Invention
The invention relates to a cooling device, in particular a cooling device for an LED lamp, comprising a fan having a fan wheel, and comprising a heat sink, through which air flows for cooling purposes when the fan wheel rotates.
2. Description of the Related Art
Compared with conventional incandescent lamps, LED lamps have a significantly longer lifetime and a likewise significantly lower energy consumption. Compared with energy-saving lamps, the average lifetime in the case of LED lamps is significantly longer given approximately the same energy consumption, and so the usually higher production costs in the case of LED lamps are justified. In the case of LED lamps there is the difficulty that it is necessary to cool the LED elements with high power. To dissipate the heat, heat sinks are generally used which effect passive or active cooling. In order to achieve the required cooling effect in conjunction with a compact design, there are already numerous proposals in the prior art.
U.S. 2005/0174780 discloses an LED lamp having a heat sink, which can be cooled by a fan built into the latter. The heat sink has radially extending walls between which the air generated by the fan can flow through in order to dissipate the heat generated by LED components.
U.S. 2006/0193139 discloses an LED lamp likewise having a heat sink and a fan. The fan draws in air radially and emits it axially to the heat sink.
EP 1 998 108 discloses an LED lamp having a substantially tubular housing, in which a fan and a heat sink are arranged. When the fan is running, an air flow is generated in the housing, said air flow in turn generating a further air flow, which flows through side openings.
WO 2008/103676 discloses an LED lamp having an oscillating plate for generating an air flow.
U.S. 2008/0212332 discloses an LED lamp which is cooled with a liquid, and in particular water.
The invention is based on the object of providing a cooling device of the above-mentioned type which is suitable, in particular, for cooling an LED lamp and which can be embodied even more compactly with the same or higher power.
The object is achieved in the case of a cooling device of the generic type by virtue of the fact that the heat sink has guide vanes deviating from the radial direction and is embodied as an integral shaped part. The guide vanes deviating from the radial direction enable an optimum air deflection and a largest possible surface contact for the heat sink. The embodiment of the guide vanes substantially has the advantage that direct access to the edge of the fan is prevented.
A particularly compact design arises when, in accordance with one development of the invention, the fan is integrated into the heat sink.
A particularly effective cooling effect and large surface contact arise when, in accordance with one development of the invention, the guide vanes are embodied in spiral fashion.
One development of the invention provides for the guide vanes to be integrally formed on a plate having an outer side, on which the components to be cooled can be fixed. The guide vanes can extend in one axial direction or else in both axial directions of said plate. The plate is preferably planar, for example square or round.
One development of the invention provides for the heat sink to be embodied substantially in pear-shaped fashion. Such a heat sink is suitable, in particular, for an LED lamp.
One development of the invention provides for the fan to have a motor circuit board, and for the heat sink to have a support for the bearing accommodation and the fixing of the motor circuit board. This likewise enables a very compact design and cost-effective production.
The invention additionally relates to a lamp comprising a cooling device according to the invention. In this case, the cooling device forms a built-in unit composed of the heat sink and the fan. The lamp is, in particular, an LED lamp, wherein the LED elements are fixed directly on the heat sink. The use of the cooling device for a lamp is the preferred application. In principle, the cooling device according to the invention could also be used for cooling other components, in particular electronic components.
Further advantageous features emerge from the dependent patent claims, the description below, and also the drawings.
Exemplary embodiments of the invention are explained in greater detail below with reference to the drawings, in which:
Air channels 8 extending axially and outwards are arranged between the guide vanes 7. As can be seen, said air channels 8 extend axially beyond the surfaces 10 and 11. An air flow generated by the fan 12 is diverted in a radial direction by the guide vanes 7. An outflow of the air already takes place at the level of a fan wheel 13 of the fan 12. As a result, the plate 9 is cooled by the guide vanes 17 surrounding it with high power. The heat sink 6 is therefore actively cooled by air flowing through. The heat sink 6 together with the fan 12 forms one unit, which, by way of example, in accordance with
The cooling device 3 shown in
The cooling device 4 shown in
The cooling device 5 shown in
The lamp 22 shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 09 405 231.3 | Dec 2009 | EP | regional |
